The seven self-fertilised plants from the crossed plants here average 15.73, and the seven self-fertilised from the self-fertilised 21 inches in height; or as 100 to 133.  Strictly analogous experiments with Viola tricolor and Lathyrus odoratus gave a very different result.

Table 5/73.  Nemophila insignis.

Heights of plants measured in inches.

Column 1:  Number (Name) of Pot.

Column 2:  Self-fertilised Plants from Crossed Plants.

Column 3:  Self-fertilised Plants from Self-fertilised Plants.

Pot 1 :  27 :  27 4/8. 
Pot 1 :  14 :  34 2/8.

Pot 2 :  17 6/8 :  23. 
Pot 2 :  24 4/8 :  32.

Pot 3 :  16 :  7.

Pot 4 :  5 3/8 :  7 2/8. 
Pot 4 :  5 4/8 :  16.

Total :  110.13 :  147.00.

23.  Boraginaceae.—­Borago officinalis.

This plant is frequented by a greater number of bees than any other one which I have observed.  It is strongly proterandrous (H.  Muller ‘Befruchtung’ etc. page 267), and the flowers can hardly fail to be cross-fertilised; but should this not occur, they are capable of self-fertilisation to a limited extent, as some pollen long remains within the anthers, and is apt to fall on the mature stigma.  In the year 1863 I covered up a plant, and examined thirty-five flowers, of which only twelve yielded any seeds; whereas of thirty-five flowers on an exposed plant growing close by, all with the exception of two yielded seeds.  The covered-up plant, however, produced altogether twenty-five spontaneously self-fertilised seeds; the exposed plant producing fifty-five seeds, the product, no doubt, of cross-fertilisation.

In the year 1868 eighteen flowers on a protected plant were crossed with pollen from a distinct plant, but only seven of these produced fruit; and I suspect that I applied pollen to many of the stigmas before they were mature.  These fruits contained on an average 2 seeds, with a maximum in one of three seeds.  Twenty-four spontaneously self-fertilised fruits were produced by the same plant, and these contained on an average 1.2 seeds, with a maximum of two in one fruit.  So that the fruits from the artificially crossed flowers yielded seeds compared with those from the spontaneously self-fertilised flowers, in the ratio of 100 to 60.  But the self-fertilised seeds, as often occurs when few are produced, were heavier than the crossed seeds in the ratio of 100 to 90.

These two lots of seeds were sown on opposite sides of two large pots; but I succeeded in raising only four pairs of equal age.  When the seedlings on both sides were about 8 inches in height they were equal.  When in full flower they were measured, as follows:—­

Table 5/74.  Borago officinalis.

Heights of plants measured in inches.

Column 1:  Number (Name) of Pot.

Column 2:  Crossed Plants.